Zombie thread, I know, but ...
I measure the fuel selector on a SN '93 with calipers, believing it to be M20x1.5mm size. Looking for a panel nut of that size... well they exist, even in stainless, but I can't easily find onesy-twosy to buy at all kinds of industrial or electrical suppliers. You can search amzn for "m20x1.5 nut" and find these cable connecting waterproof widgets with that nut; 10 for like $7 when I looked. Plastic. Keep the nut, scrap the rest of the assembly. If I find a way to buy them in stainless (after confirming the size), for say $2 each for some reasonable quantity, I might get a bunch and post back that they are available.